#ifndef DES_H
#define DES_H

#include <bitset>
#include <iostream>
#include <QVector>

using std::cout;
using std::endl;
using std::bitset;

class des
{
private:
    bitset<64> key;         // 64位密钥
    bitset<48> subKey[16];  // 存放16轮子密钥
    bitset<64> plain;       // 明文解析 -> 二进制
    bitset<64> cipher;      // 密文 - 二进制
    bitset<64> deplain;     // 用密文解析出的明文
//    bitset<48> desubKey[16];  // 解密过程存放16轮子密钥

    // 初始置换表
    int IP[64] = {58, 50, 42, 34, 26, 18, 10, 2,
                60, 52, 44, 36, 28, 20, 12, 4,
                62, 54, 46, 38, 30, 22, 14, 6,
                64, 56, 48, 40, 32, 24, 16, 8,
                57, 49, 41, 33, 25, 17, 9,  1,
                59, 51, 43, 35, 27, 19, 11, 3,
                61, 53, 45, 37, 29, 21, 13, 5,
                63, 55, 47, 39, 31, 23, 15, 7};

    // 结尾置换表
    int IP_1[64] = {40, 8, 48, 16, 56, 24, 64, 32,
                  39, 7, 47, 15, 55, 23, 63, 31,
                  38, 6, 46, 14, 54, 22, 62, 30,
                  37, 5, 45, 13, 53, 21, 61, 29,
                  36, 4, 44, 12, 52, 20, 60, 28,
                  35, 3, 43, 11, 51, 19, 59, 27,
                  34, 2, 42, 10, 50, 18, 58, 26,
                  33, 1, 41,  9, 49, 17, 57, 25};

    /*------------------下面是生成密钥所用表-----------------*/

    // 密钥置换表，将64位密钥变成56位
    int PC_1[56] = {57, 49, 41, 33, 25, 17, 9,
                   1, 58, 50, 42, 34, 26, 18,
                  10,  2, 59, 51, 43, 35, 27,
                  19, 11,  3, 60, 52, 44, 36,
                  63, 55, 47, 39, 31, 23, 15,
                   7, 62, 54, 46, 38, 30, 22,
                  14,  6, 61, 53, 45, 37, 29,
                  21, 13,  5, 28, 20, 12,  4};

    // 压缩置换，将56位密钥压缩成48位子密钥
    int PC_2[48] = {14, 17, 11, 24,  1,  5,
                   3, 28, 15,  6, 21, 10,
                  23, 19, 12,  4, 26,  8,
                  16,  7, 27, 20, 13,  2,
                  41, 52, 31, 37, 47, 55,
                  30, 40, 51, 45, 33, 48,
                  44, 49, 39, 56, 34, 53,
                  46, 42, 50, 36, 29, 32};

    // 每轮左移的位数
    int shiftBits[16] = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};

    /*------------------下面是密码函数 f 所用表-----------------*/

    // 扩展置换表，将 32位 扩展至 48位
    int E[48] = {32,  1,  2,  3,  4,  5,
                4,  5,  6,  7,  8,  9,
                8,  9, 10, 11, 12, 13,
               12, 13, 14, 15, 16, 17,
               16, 17, 18, 19, 20, 21,
               20, 21, 22, 23, 24, 25,
               24, 25, 26, 27, 28, 29,
               28, 29, 30, 31, 32,  1};

    // S盒，每个S盒是4x16的置换表，6位 -> 4位
    int S_BOX[8][4][16] = {
        {
            {14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},
            {0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},
            {4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},
            {15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}
        },
        {
            {15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},
            {3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},
            {0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},
            {13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}
        },
        {
            {10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},
            {13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},
            {13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},
            {1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}
        },
        {
            {7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},
            {13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},
            {10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},
            {3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}
        },
        {
            {2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},
            {14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},
            {4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},
            {11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}
        },
        {
            {12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},
            {10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},
            {9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},
            {4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}
        },
        {
            {4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},
            {13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},
            {1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},
            {6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}
        },
        {
            {13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},
            {1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},
            {7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},
            {2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}
        }
    };

    // P置换，32位 -> 32位
    int P[32] = {16,  7, 20, 21,
               29, 12, 28, 17,
                1, 15, 23, 26,
                5, 18, 31, 10,
                2,  8, 24, 14,
               32, 27,  3,  9,
               19, 13, 30,  6,
               22, 11,  4, 25 };

public:
    des();

    QVector<bitset<32> > leftTempKey;    //16轮的左侧输入,用于GUI显示
    QVector<bitset<32> > rightTempkey;   //16轮的右侧输入，用于GUI显示

    void setKey(bitset<64> theKey);

    bitset<64> getKey();

    void setPlain(bitset<64> thePlain);

    bitset<64> getPlain();

    void setCipher(bitset<64> theCipher);

    bitset<64> getCipher();

    bitset<64> getDeplain();

    /**********************************************************************/
    /*                                                                    */
    /*                            下面是DES算法实现                         */
    /*                                                                    */
    /**********************************************************************/

    /**
     *  密码函数f，接收32位数据和48位子密钥，产生一个32位的输出
     */
    bitset<32> f(bitset<32> R, bitset<48> k);

    /**
     *  对56位密钥的前后部分进行左移
     */
    bitset<28> leftShift(bitset<28> k, int shift);

    /**
     *  生成16个48位的子密钥
     */
    void generateKeys();

    /**
     *  工具函数：将char字符数组转为二进制
     */
    bitset<64> charToBitset(const char s[8]);

    /**
     *  DES加密
     */
    void encrypt();

    /**
     *  DES解密
     */
    void decrypt();
};

#endif // DES_H
